/* Copyright  2009
   @Author
   Richard Changde Yin            e-mail yinchangde@hotmail.com

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
   
/**
 *@filename: period_diff.cc
 */ 
#include "server_includes.h"
#include CSTDINT_H
#include "function/time/period_diff.h"
#include "calendar.h"

int64_t Item_func_period_diff::val_int()
{
  assert(fixed == 1);
  uint32_t period1= (uint32_t)args[0]->val_int();
  uint32_t period2= (uint32_t)args[1]->val_int();

  if ((null_value=args[0]->null_value || args[1]->null_value))
    return 0; /* purecov: inspected */
  return (int64_t) (year_month_to_months(period1) -
                    year_month_to_months(period2));
}
